Merge branch 'lvs-next-2.6' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/lvs-2.6

Conflicts:

	net/netfilter/Kconfig

27 files changed, 14242 insertions, 0 deletions

diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index f70b4145ffc..78892cf2b02 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -858,3 +858,5 @@ config NETFILTER_XT_MATCH_U32
 endif # NETFILTER_XTABLES
 
 endmenu
+
+source "net/netfilter/ipvs/Kconfig"
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 8ce67665882..da3d909e053 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -89,3 +89,6 @@ obj-$(CONFIG_NETFILTER_XT_MATCH_STRING) += xt_string.o
 obj-$(CONFIG_NETFILTER_XT_MATCH_TCPMSS) += xt_tcpmss.o
 obj-$(CONFIG_NETFILTER_XT_MATCH_TIME) += xt_time.o
 obj-$(CONFIG_NETFILTER_XT_MATCH_U32) += xt_u32.o
+
+# IPVS
+obj-$(CONFIG_IP_VS) += ipvs/
diff --git a/net/netfilter/ipvs/Kconfig b/net/netfilter/ipvs/Kconfig
new file mode 100644
index 00000000000..de6004de80b
--- /dev/null
+++ b/net/netfilter/ipvs/Kconfig
@@ -0,0 +1,239 @@
+#
+# IP Virtual Server configuration
+#
+menuconfig IP_VS
+	tristate "IP virtual server support (EXPERIMENTAL)"
+	depends on NETFILTER
+	---help---
+	  IP Virtual Server support will let you build a high-performance
+	  virtual server based on cluster of two or more real servers. This
+	  option must be enabled for at least one of the clustered computers
+	  that will take care of intercepting incoming connections to a
+	  single IP address and scheduling them to real servers.
+
+	  Three request dispatching techniques are implemented, they are
+	  virtual server via NAT, virtual server via tunneling and virtual
+	  server via direct routing. The several scheduling algorithms can
+	  be used to choose which server the connection is directed to,
+	  thus load balancing can be achieved among the servers.  For more
+	  information and its administration program, please visit the
+	  following URL: <http://www.linuxvirtualserver.org/>.
+
+	  If you want to compile it in kernel, say Y. To compile it as a
+	  module, choose M here. If unsure, say N.
+
+if IP_VS
+
+config	IP_VS_IPV6
+	bool "IPv6 support for IPVS (DANGEROUS)"
+	depends on EXPERIMENTAL && (IPV6 = y || IP_VS = IPV6)
+	---help---
+	  Add IPv6 support to IPVS. This is incomplete and might be dangerous.
+
+	  Say N if unsure.
+
+config	IP_VS_DEBUG
+	bool "IP virtual server debugging"
+	---help---
+	  Say Y here if you want to get additional messages useful in
+	  debugging the IP virtual server code. You can change the debug
+	  level in /proc/sys/net/ipv4/vs/debug_level
+
+config	IP_VS_TAB_BITS
+	int "IPVS connection table size (the Nth power of 2)"
+	range 8 20
+	default 12
+	---help---
+	  The IPVS connection hash table uses the chaining scheme to handle
+	  hash collisions. Using a big IPVS connection hash table will greatly
+	  reduce conflicts when there are hundreds of thousands of connections
+	  in the hash table.
+
+	  Note the table size must be power of 2. The table size will be the
+	  value of 2 to the your input number power. The number to choose is
+	  from 8 to 20, the default number is 12, which means the table size
+	  is 4096. Don't input the number too small, otherwise you will lose
+	  performance on it. You can adapt the table size yourself, according
+	  to your virtual server application. It is good to set the table size
+	  not far less than the number of connections per second multiplying
+	  average lasting time of connection in the table.  For example, your
+	  virtual server gets 200 connections per second, the connection lasts
+	  for 200 seconds in average in the connection table, the table size
+	  should be not far less than 200x200, it is good to set the table
+	  size 32768 (2**15).
+
+	  Another note that each connection occupies 128 bytes effectively and
+	  each hash entry uses 8 bytes, so you can estimate how much memory is
+	  needed for your box.
+
+comment "IPVS transport protocol load balancing support"
+
+config	IP_VS_PROTO_TCP
+	bool "TCP load balancing support"
+	---help---
+	  This option enables support for load balancing TCP transport
+	  protocol. Say Y if unsure.
+
+config	IP_VS_PROTO_UDP
+	bool "UDP load balancing support"
+	---help---
+	  This option enables support for load balancing UDP transport
+	  protocol. Say Y if unsure.
+
+config	IP_VS_PROTO_AH_ESP
+	bool
+	depends on UNDEFINED
+
+config	IP_VS_PROTO_ESP
+	bool "ESP load balancing support"
+	select IP_VS_PROTO_AH_ESP
+	---help---
+	  This option enables support for load balancing ESP (Encapsulation
+	  Security Payload) transport protocol. Say Y if unsure.
+
+config	IP_VS_PROTO_AH
+	bool "AH load balancing support"
+	select IP_VS_PROTO_AH_ESP
+	---help---
+	  This option enables support for load balancing AH (Authentication
+	  Header) transport protocol. Say Y if unsure.
+
+comment "IPVS scheduler"
+
+config	IP_VS_RR
+	tristate "round-robin scheduling"
+	---help---
+	  The robin-robin scheduling algorithm simply directs network
+	  connections to different real servers in a round-robin manner.
+
+	  If you want to compile it in kernel, say Y. To compile it as a
+	  module, choose M here. If unsure, say N.
+ 
+config	IP_VS_WRR
+        tristate "weighted round-robin scheduling" 
+	---help---
+	  The weighted robin-robin scheduling algorithm directs network
+	  connections to different real servers based on server weights
+	  in a round-robin manner. Servers with higher weights receive
+	  new connections first than those with less weights, and servers
+	  with higher weights get more connections than those with less
+	  weights and servers with equal weights get equal connections.
+
+	  If you want to compile it in kernel, say Y. To compile it as a
+	  module, choose M here. If unsure, say N.
+
+config	IP_VS_LC
+        tristate "least-connection scheduling"
+	---help---
+	  The least-connection scheduling algorithm directs network
+	  connections to the server with the least number of active 
+	  connections.
+
+	  If you want to compile it in kernel, say Y. To compile it as a
+	  module, choose M here. If unsure, say N.
+
+config	IP_VS_WLC
+        tristate "weighted least-connection scheduling"
+	---help---
+	  The weighted least-connection scheduling algorithm directs network
+	  connections to the server with the least active connections
+	  normalized by the server weight.
+
+	  If you want to compile it in kernel, say Y. To compile it as a
+	  module, choose M here. If unsure, say N.
+
+config	IP_VS_LBLC
+	tristate "locality-based least-connection scheduling"
+	---help---
+	  The locality-based least-connection scheduling algorithm is for
+	  destination IP load balancing. It is usually used in cache cluster.
+	  This algorithm usually directs packet destined for an IP address to
+	  its server if the server is alive and under load. If the server is
+	  overloaded (its active connection numbers is larger than its weight)
+	  and there is a server in its half load, then allocate the weighted
+	  least-connection server to this IP address.
+
+	  If you want to compile it in kernel, say Y. To compile it as a
+	  module, choose M here. If unsure, say N.
+
+config  IP_VS_LBLCR
+	tristate "locality-based least-connection with replication scheduling"
+	---help---
+	  The locality-based least-connection with replication scheduling
+	  algorithm is also for destination IP load balancing. It is 
+	  usually used in cache cluster. It differs from the LBLC scheduling
+	  as follows: the load balancer maintains mappings from a target
+	  to a set of server nodes that can serve the target. Requests for
+	  a target are assigned to the least-connection node in the target's
+	  server set. If all the node in the server set are over loaded,
+	  it picks up a least-connection node in the cluster and adds it
+	  in the sever set for the target. If the server set has not been
+	  modified for the specified time, the most loaded node is removed
+	  from the server set, in order to avoid high degree of replication.
+
+	  If you want to compile it in kernel, say Y. To compile it as a
+	  module, choose M here. If unsure, say N.
+
+config	IP_VS_DH
+	tristate "destination hashing scheduling"
+	---help---
+	  The destination hashing scheduling algorithm assigns network
+	  connections to the servers through looking up a statically assigned
+	  hash table by their destination IP addresses.
+
+	  If you want to compile it in kernel, say Y. To compile it as a
+	  module, choose M here. If unsure, say N.
+
+config	IP_VS_SH
+	tristate "source hashing scheduling"
+	---help---
+	  The source hashing scheduling algorithm assigns network
+	  connections to the servers through looking up a statically assigned
+	  hash table by their source IP addresses.
+
+	  If you want to compile it in kernel, say Y. To compile it as a
+	  module, choose M here. If unsure, say N.
+
+config	IP_VS_SED
+	tristate "shortest expected delay scheduling"
+	---help---
+	  The shortest expected delay scheduling algorithm assigns network
+	  connections to the server with the shortest expected delay. The 
+	  expected delay that the job will experience is (Ci + 1) / Ui if 
+	  sent to the ith server, in which Ci is the number of connections
+	  on the ith server and Ui is the fixed service rate (weight)
+	  of the ith server.
+
+	  If you want to compile it in kernel, say Y. To compile it as a
+	  module, choose M here. If unsure, say N.
+
+config	IP_VS_NQ
+	tristate "never queue scheduling"
+	---help---
+	  The never queue scheduling algorithm adopts a two-speed model.
+	  When there is an idle server available, the job will be sent to
+	  the idle server, instead of waiting for a fast one. When there
+	  is no idle server available, the job will be sent to the server
+	  that minimize its expected delay (The Shortest Expected Delay
+	  scheduling algorithm).
+
+	  If you want to compile it in kernel, say Y. To compile it as a
+	  module, choose M here. If unsure, say N.
+
+comment 'IPVS application helper'
+
+config	IP_VS_FTP
+  	tristate "FTP protocol helper"
+        depends on IP_VS_PROTO_TCP
+	---help---
+	  FTP is a protocol that transfers IP address and/or port number in
+	  the payload. In the virtual server via Network Address Translation,
+	  the IP address and port number of real servers cannot be sent to
+	  clients in ftp connections directly, so FTP protocol helper is
+	  required for tracking the connection and mangling it back to that of
+	  virtual service.
+
+	  If you want to compile it in kernel, say Y. To compile it as a
+	  module, choose M here. If unsure, say N.
+
+endif # IP_VS
diff --git a/net/netfilter/ipvs/Makefile b/net/netfilter/ipvs/Makefile
new file mode 100644
index 00000000000..73a46fe1fe4
--- /dev/null
+++ b/net/netfilter/ipvs/Makefile
@@ -0,0 +1,33 @@
+#
+# Makefile for the IPVS modules on top of IPv4.
+#
+
+# IPVS transport protocol load balancing support
+ip_vs_proto-objs-y :=
+ip_vs_proto-objs-$(CONFIG_IP_VS_PROTO_TCP) += ip_vs_proto_tcp.o
+ip_vs_proto-objs-$(CONFIG_IP_VS_PROTO_UDP) += ip_vs_proto_udp.o
+ip_vs_proto-objs-$(CONFIG_IP_VS_PROTO_AH_ESP) += ip_vs_proto_ah_esp.o
+
+ip_vs-objs :=	ip_vs_conn.o ip_vs_core.o ip_vs_ctl.o ip_vs_sched.o	   \
+		ip_vs_xmit.o ip_vs_app.o ip_vs_sync.o	   		   \
+		ip_vs_est.o ip_vs_proto.o 				   \
+		$(ip_vs_proto-objs-y)
+
+
+# IPVS core
+obj-$(CONFIG_IP_VS) += ip_vs.o
+
+# IPVS schedulers
+obj-$(CONFIG_IP_VS_RR) += ip_vs_rr.o
+obj-$(CONFIG_IP_VS_WRR) += ip_vs_wrr.o
+obj-$(CONFIG_IP_VS_LC) += ip_vs_lc.o
+obj-$(CONFIG_IP_VS_WLC) += ip_vs_wlc.o
+obj-$(CONFIG_IP_VS_LBLC) += ip_vs_lblc.o
+obj-$(CONFIG_IP_VS_LBLCR) += ip_vs_lblcr.o
+obj-$(CONFIG_IP_VS_DH) += ip_vs_dh.o
+obj-$(CONFIG_IP_VS_SH) += ip_vs_sh.o
+obj-$(CONFIG_IP_VS_SED) += ip_vs_sed.o
+obj-$(CONFIG_IP_VS_NQ) += ip_vs_nq.o
+
+# IPVS application helpers
+obj-$(CONFIG_IP_VS_FTP) += ip_vs_ftp.o
diff --git a/net/netfilter/ipvs/ip_vs_app.c b/net/netfilter/ipvs/ip_vs_app.c
new file mode 100644
index 00000000000..201b8ea3020
--- /dev/null
+++ b/net/netfilter/ipvs/ip_vs_app.c
@@ -0,0 +1,622 @@
+/*
+ * ip_vs_app.c: Application module support for IPVS
+ *
+ * Authors:     Wensong Zhang <wensong@linuxvirtualserver.org>
+ *
+ *              This program is free software; you can redistribute it and/or
+ *              modify it under the terms of the GNU General Public License
+ *              as published by the Free Software Foundation; either version
+ *              2 of the License, or (at your option) any later version.
+ *
+ * Most code here is taken from ip_masq_app.c in kernel 2.2. The difference
+ * is that ip_vs_app module handles the reverse direction (incoming requests
+ * and outgoing responses).
+ *
+ *		IP_MASQ_APP application masquerading module
+ *
+ * Author:	Juan Jose Ciarlante, <jjciarla@raiz.uncu.edu.ar>
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/in.h>
+#include <linux/ip.h>
+#include <linux/netfilter.h>
+#include <net/net_namespace.h>
+#include <net/protocol.h>
+#include <net/tcp.h>
+#include <asm/system.h>
+#include <linux/stat.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/mutex.h>
+
+#include <net/ip_vs.h>
+
+EXPORT_SYMBOL(register_ip_vs_app);
+EXPORT_SYMBOL(unregister_ip_vs_app);
+EXPORT_SYMBOL(register_ip_vs_app_inc);
+
+/* ipvs application list head */
+static LIST_HEAD(ip_vs_app_list);
+static DEFINE_MUTEX(__ip_vs_app_mutex);
+
+
+/*
+ *	Get an ip_vs_app object
+ */
+static inline int ip_vs_app_get(struct ip_vs_app *app)
+{
+	return try_module_get(app->module);
+}
+
+
+static inline void ip_vs_app_put(struct ip_vs_app *app)
+{
+	module_put(app->module);
+}
+
+
+/*
+ *	Allocate/initialize app incarnation and register it in proto apps.
+ */
+static int
+ip_vs_app_inc_new(struct ip_vs_app *app, __u16 proto, __u16 port)
+{
+	struct ip_vs_protocol *pp;
+	struct ip_vs_app *inc;
+	int ret;
+
+	if (!(pp = ip_vs_proto_get(proto)))
+		return -EPROTONOSUPPORT;
+
+	if (!pp->unregister_app)
+		return -EOPNOTSUPP;
+
+	inc = kmemdup(app, sizeof(*inc), GFP_KERNEL);
+	if (!inc)
+		return -ENOMEM;
+	INIT_LIST_HEAD(&inc->p_list);
+	INIT_LIST_HEAD(&inc->incs_list);
+	inc->app = app;
+	inc->port = htons(port);
+	atomic_set(&inc->usecnt, 0);
+
+	if (app->timeouts) {
+		inc->timeout_table =
+			ip_vs_create_timeout_table(app->timeouts,
+						   app->timeouts_size);
+		if (!inc->timeout_table) {
+			ret = -ENOMEM;
+			goto out;
+		}
+	}
+
+	ret = pp->register_app(inc);
+	if (ret)
+		goto out;
+
+	list_add(&inc->a_list, &app->incs_list);
+	IP_VS_DBG(9, "%s application %s:%u registered\n",
+		  pp->name, inc->name, inc->port);
+
+	return 0;
+
+  out:
+	kfree(inc->timeout_table);
+	kfree(inc);
+	return ret;
+}
+
+
+/*
+ *	Release app incarnation
+ */
+static void
+ip_vs_app_inc_release(struct ip_vs_app *inc)
+{
+	struct ip_vs_protocol *pp;
+
+	if (!(pp = ip_vs_proto_get(inc->protocol)))
+		return;
+
+	if (pp->unregister_app)
+		pp->unregister_app(inc);
+
+	IP_VS_DBG(9, "%s App %s:%u unregistered\n",
+		  pp->name, inc->name, inc->port);
+
+	list_del(&inc->a_list);
+
+	kfree(inc->timeout_table);
+	kfree(inc);
+}
+
+
+/*
+ *	Get reference to app inc (only called from softirq)
+ *
+ */
+int ip_vs_app_inc_get(struct ip_vs_app *inc)
+{
+	int result;
+
+	atomic_inc(&inc->usecnt);
+	if (unlikely((result = ip_vs_app_get(inc->app)) != 1))
+		atomic_dec(&inc->usecnt);
+	return result;
+}
+
+
+/*
+ *	Put the app inc (only called from timer or net softirq)
+ */
+void ip_vs_app_inc_put(struct ip_vs_app *inc)
+{
+	ip_vs_app_put(inc->app);
+	atomic_dec(&inc->usecnt);
+}
+
+
+/*
+ *	Register an application incarnation in protocol applications
+ */
+int
+register_ip_vs_app_inc(struct ip_vs_app *app, __u16 proto, __u16 port)
+{
+	int result;
+
+	mutex_lock(&__ip_vs_app_mutex);
+
+	result = ip_vs_app_inc_new(app, proto, port);
+
+	mutex_unlock(&__ip_vs_app_mutex);
+
+	return result;
+}
+
+
+/*
+ *	ip_vs_app registration routine
+ */
+int register_ip_vs_app(struct ip_vs_app *app)
+{
+	/* increase the module use count */
+	ip_vs_use_count_inc();
+
+	mutex_lock(&__ip_vs_app_mutex);
+
+	list_add(&app->a_list, &ip_vs_app_list);
+
+	mutex_unlock(&__ip_vs_app_mutex);
+
+	return 0;
+}
+
+
+/*
+ *	ip_vs_app unregistration routine
+ *	We are sure there are no app incarnations attached to services
+ */
+void unregister_ip_vs_app(struct ip_vs_app *app)
+{
+	struct ip_vs_app *inc, *nxt;
+
+	mutex_lock(&__ip_vs_app_mutex);
+
+	list_for_each_entry_safe(inc, nxt, &app->incs_list, a_list) {
+		ip_vs_app_inc_release(inc);
+	}
+
+	list_del(&app->a_list);
+
+	mutex_unlock(&__ip_vs_app_mutex);
+
+	/* decrease the module use count */
+	ip_vs_use_count_dec();
+}
+
+
+/*
+ *	Bind ip_vs_conn to its ip_vs_app (called by cp constructor)
+ */
+int ip_vs_bind_app(struct ip_vs_conn *cp, struct ip_vs_protocol *pp)
+{
+	return pp->app_conn_bind(cp);
+}
+
+
+/*
+ *	Unbind cp from application incarnation (called by cp destructor)
+ */
+void ip_vs_unbind_app(struct ip_vs_conn *cp)
+{
+	struct ip_vs_app *inc = cp->app;
+
+	if (!inc)
+		return;
+
+	if (inc->unbind_conn)
+		inc->unbind_conn(inc, cp);
+	if (inc->done_conn)
+		inc->done_conn(inc, cp);
+	ip_vs_app_inc_put(inc);
+	cp->app = NULL;
+}
+
+
+/*
+ *	Fixes th->seq based on ip_vs_seq info.
+ */
+static inline void vs_fix_seq(const struct ip_vs_seq *vseq, struct tcphdr *th)
+{
+	__u32 seq = ntohl(th->seq);
+
+	/*
+	 *	Adjust seq with delta-offset for all packets after
+	 *	the most recent resized pkt seq and with previous_delta offset
+	 *	for all packets	before most recent resized pkt seq.
+	 */
+	if (vseq->delta || vseq->previous_delta) {
+		if(after(seq, vseq->init_seq)) {
+			th->seq = htonl(seq + vseq->delta);
+			IP_VS_DBG(9, "vs_fix_seq(): added delta (%d) to seq\n",
+				  vseq->delta);
+		} else {
+			th->seq = htonl(seq + vseq->previous_delta);
+			IP_VS_DBG(9, "vs_fix_seq(): added previous_delta "
+				  "(%d) to seq\n", vseq->previous_delta);
+		}
+	}
+}
+
+
+/*
+ *	Fixes th->ack_seq based on ip_vs_seq info.
+ */
+static inline void
+vs_fix_ack_seq(const struct ip_vs_seq *vseq, struct tcphdr *th)
+{
+	__u32 ack_seq = ntohl(th->ack_seq);
+
+	/*
+	 * Adjust ack_seq with delta-offset for
+	 * the packets AFTER most recent resized pkt has caused a shift
+	 * for packets before most recent resized pkt, use previous_delta
+	 */
+	if (vseq->delta || vseq->previous_delta) {
+		/* since ack_seq is the number of octet that is expected
+		   to receive next, so compare it with init_seq+delta */
+		if(after(ack_seq, vseq->init_seq+vseq->delta)) {
+			th->ack_seq = htonl(ack_seq - vseq->delta);
+			IP_VS_DBG(9, "vs_fix_ack_seq(): subtracted delta "
+				  "(%d) from ack_seq\n", vseq->delta);
+
+		} else {
+			th->ack_seq = htonl(ack_seq - vseq->previous_delta);
+			IP_VS_DBG(9, "vs_fix_ack_seq(): subtracted "
+				  "previous_delta (%d) from ack_seq\n",
+				  vseq->previous_delta);
+		}
+	}
+}
+
+
+/*
+ *	Updates ip_vs_seq if pkt has been resized
+ *	Assumes already checked proto==IPPROTO_TCP and diff!=0.
+ */
+static inline void vs_seq_update(struct ip_vs_conn *cp, struct ip_vs_seq *vseq,
+				 unsigned flag, __u32 seq, int diff)
+{
+	/* spinlock is to keep updating cp->flags atomic */
+	spin_lock(&cp->lock);
+	if (!(cp->flags & flag) || after(seq, vseq->init_seq)) {
+		vseq->previous_delta = vseq->delta;
+		vseq->delta += diff;
+		vseq->init_seq = seq;
+		cp->flags |= flag;
+	}
+	spin_unlock(&cp->lock);
+}
+
+static inline int app_tcp_pkt_out(struct ip_vs_conn *cp, struct sk_buff *skb,
+				  struct ip_vs_app *app)
+{
+	int diff;
+	const unsigned int tcp_offset = ip_hdrlen(skb);
+	struct tcphdr *th;
+	__u32 seq;
+
+	if (!skb_make_writable(skb, tcp_offset + sizeof(*th)))
+		return 0;
+
+	th = (struct tcphdr *)(skb_network_header(skb) + tcp_offset);
+
+	/*
+	 *	Remember seq number in case this pkt gets resized
+	 */
+	seq = ntohl(th->seq);
+
+	/*
+	 *	Fix seq stuff if flagged as so.
+	 */
+	if (cp->flags & IP_VS_CONN_F_OUT_SEQ)
+		vs_fix_seq(&cp->out_seq, th);
+	if (cp->flags & IP_VS_CONN_F_IN_SEQ)
+		vs_fix_ack_seq(&cp->in_seq, th);
+
+	/*
+	 *	Call private output hook function
+	 */
+	if (app->pkt_out == NULL)
+		return 1;
+
+	if (!app->pkt_out(app, cp, skb, &diff))
+		return 0;
+
+	/*
+	 *	Update ip_vs seq stuff if len has changed.
+	 */
+	if (diff != 0)
+		vs_seq_update(cp, &cp->out_seq,
+			      IP_VS_CONN_F_OUT_SEQ, seq, diff);
+
+	return 1;
+}
+
+/*
+ *	Output pkt hook. Will call bound ip_vs_app specific function
+ *	called by ipvs packet handler, assumes previously checked cp!=NULL
+ *	returns false if it can't handle packet (oom)
+ */
+int ip_vs_app_pkt_out(struct ip_vs_conn *cp, struct sk_buff *skb)
+{
+	struct ip_vs_app *app;
+
+	/*
+	 *	check if application module is bound to
+	 *	this ip_vs_conn.
+	 */
+	if ((app = cp->app) == NULL)
+		return 1;
+
+	/* TCP is complicated */
+	if (cp->protocol == IPPROTO_TCP)
+		return app_tcp_pkt_out(cp, skb, app);
+
+	/*
+	 *	Call private output hook function
+	 */
+	if (app->pkt_out == NULL)
+		return 1;
+
+	return app->pkt_out(app, cp, skb, NULL);
+}
+
+
+static inline int app_tcp_pkt_in(struct ip_vs_conn *cp, struct sk_buff *skb,
+				 struct ip_vs_app *app)
+{
+	int diff;
+	const unsigned int tcp_offset = ip_hdrlen(skb);
+	struct tcphdr *th;
+	__u32 seq;
+
+	if (!skb_make_writable(skb, tcp_offset + sizeof(*th)))
+		return 0;
+
+	th = (struct tcphdr *)(skb_network_header(skb) + tcp_offset);
+
+	/*
+	 *	Remember seq number in case this pkt gets resized
+	 */
+	seq = ntohl(th->seq);
+
+	/*
+	 *	Fix seq stuff if flagged as so.
+	 */
+	if (cp->flags & IP_VS_CONN_F_IN_SEQ)
+		vs_fix_seq(&cp->in_seq, th);
+	if (cp->flags & IP_VS_CONN_F_OUT_SEQ)
+		vs_fix_ack_seq(&cp->out_seq, th);
+
+	/*
+	 *	Call private input hook function
+	 */
+	if (app->pkt_in == NULL)
+		return 1;
+
+	if (!app->pkt_in(app, cp, skb, &diff))
+		return 0;
+
+	/*
+	 *	Update ip_vs seq stuff if len has changed.
+	 */
+	if (diff != 0)
+		vs_seq_update(cp, &cp->in_seq,
+			      IP_VS_CONN_F_IN_SEQ, seq, diff);
+
+	return 1;
+}
+
+/*
+ *	Input pkt hook. Will call bound ip_vs_app specific function
+ *	called by ipvs packet handler, assumes previously checked cp!=NULL.
+ *	returns false if can't handle packet (oom).
+ */
+int ip_vs_app_pkt_in(struct ip_vs_conn *cp, struct sk_buff *skb)
+{
+	struct ip_vs_app *app;
+
+	/*
+	 *	check if application module is bound to
+	 *	this ip_vs_conn.
+	 */
+	if ((app = cp->app) == NULL)
+		return 1;
+
+	/* TCP is complicated */
+	if (cp->protocol == IPPROTO_TCP)
+		return app_tcp_pkt_in(cp, skb, app);
+
+	/*
+	 *	Call private input hook function
+	 */
+	if (app->pkt_in == NULL)
+		return 1;
+
+	return app->pkt_in(app, cp, skb, NULL);
+}
+
+
+#ifdef CONFIG_PROC_FS
+/*
+ *	/proc/net/ip_vs_app entry function
+ */
+
+static struct ip_vs_app *ip_vs_app_idx(loff_t pos)
+{
+	struct ip_vs_app *app, *inc;
+
+	list_for_each_entry(app, &ip_vs_app_list, a_list) {
+		list_for_each_entry(inc, &app->incs_list, a_list) {
+			if (pos-- == 0)
+				return inc;
+		}
+	}
+	return NULL;
+
+}
+
+static void *ip_vs_app_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	mutex_lock(&__ip_vs_app_mutex);
+
+	return *pos ? ip_vs_app_idx(*pos - 1) : SEQ_START_TOKEN;
+}
+
+static void *ip_vs_app_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct ip_vs_app *inc, *app;
+	struct list_head *e;
+
+	++*pos;
+	if (v == SEQ_START_TOKEN)
+		return ip_vs_app_idx(0);
+
+	inc = v;
+	app = inc->app;
+
+	if ((e = inc->a_list.next) != &app->incs_list)
+		return list_entry(e, struct ip_vs_app, a_list);
+
+	/* go on to next application */
+	for (e = app->a_list.next; e != &ip_vs_app_list; e = e->next) {
+		app = list_entry(e, struct ip_vs_app, a_list);
+		list_for_each_entry(inc, &app->incs_list, a_list) {
+			return inc;
+		}
+	}
+	return NULL;
+}
+
+static void ip_vs_app_seq_stop(struct seq_file *seq, void *v)
+{
+	mutex_unlock(&__ip_vs_app_mutex);
+}
+
+static int ip_vs_app_seq_show(struct seq_file *seq, void *v)
+{
+	if (v == SEQ_START_TOKEN)
+		seq_puts(seq, "prot port    usecnt name\n");
+	else {
+		const struct ip_vs_app *inc = v;
+
+		seq_printf(seq, "%-3s  %-7u %-6d %-17s\n",
+			   ip_vs_proto_name(inc->protocol),
+			   ntohs(inc->port),
+			   atomic_read(&inc->usecnt),
+			   inc->name);
+	}
+	return 0;
+}
+
+static const struct seq_operations ip_vs_app_seq_ops = {
+	.start = ip_vs_app_seq_start,
+	.next  = ip_vs_app_seq_next,
+	.stop  = ip_vs_app_seq_stop,
+	.show  = ip_vs_app_seq_show,
+};
+
+static int ip_vs_app_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &ip_vs_app_seq_ops);
+}
+
+static const struct file_operations ip_vs_app_fops = {
+	.owner	 = THIS_MODULE,
+	.open	 = ip_vs_app_open,
+	.read	 = seq_read,
+	.llseek  = seq_lseek,
+	.release = seq_release,
+};
+#endif
+
+
+/*
+ *	Replace a segment of data with a new segment
+ */
+int ip_vs_skb_replace(struct sk_buff *skb, gfp_t pri,
+		      char *o_buf, int o_len, char *n_buf, int n_len)
+{
+	int diff;
+	int o_offset;
+	int o_left;
+
+	EnterFunction(9);
+
+	diff = n_len - o_len;
+	o_offset = o_buf - (char *)skb->data;
+	/* The length of left data after o_buf+o_len in the skb data */
+	o_left = skb->len - (o_offset + o_len);
+
+	if (diff <= 0) {
+		memmove(o_buf + n_len, o_buf + o_len, o_left);
+		memcpy(o_buf, n_buf, n_len);
+		skb_trim(skb, skb->len + diff);
+	} else if (diff <= skb_tailroom(skb)) {
+		skb_put(skb, diff);
+		memmove(o_buf + n_len, o_buf + o_len, o_left);
+		memcpy(o_buf, n_buf, n_len);
+	} else {
+		if (pskb_expand_head(skb, skb_headroom(skb), diff, pri))
+			return -ENOMEM;
+		skb_put(skb, diff);
+		memmove(skb->data + o_offset + n_len,
+			skb->data + o_offset + o_len, o_left);
+		skb_copy_to_linear_data_offset(skb, o_offset, n_buf, n_len);
+	}
+
+	/* must update the iph total length here */
+	ip_hdr(skb)->tot_len = htons(skb->len);
+
+	LeaveFunction(9);
+	return 0;
+}
+
+
+int __init ip_vs_app_init(void)
+{
+	/* we will replace it with proc_net_ipvs_create() soon */
+	proc_net_fops_create(&init_net, "ip_vs_app", 0, &ip_vs_app_fops);